1. Technical Field
The present principles generally relate to compression and transmission of images and, more particularly, to compression and transmission of industry protocol compliant images from a server to remote viewing stations.
2. Description of the Related Art
Industry protocol compliant images include digital medical images, which correspond to a class of data files that are relatively large in size and volume. A medical image volume may include multiple image “slices.” Examples of digital medical images include magnetic resonance images (MRI), ultrasound (US) images, computed tomography (CT) images, typically referred to as “CAT scans,” and positron emission tomography (PET) images, among others. Digital medical images are commonly stored, retrieved, transmitted and viewed in accordance with a standard format and communication protocol known as Digital Imaging Communications in Medicine (DICOM) in DICOM-enabled systems. DICOM is one example of an industry protocol.
DICOM images are stored in central repository servers referred to as Picture Archival and Communication Systems (PACS) servers. Remote Viewing Stations include DICOM-enabled applications that may query the PACS servers to retrieve the DICOM images for viewing. Current methods for viewing medical images entail using a DICOM enabled application to retrieve medical images from a PACS Server and to store and access them in a local storage medium. Modern medical images are rather large, utilizing up to 1 Gbyte of memory or more per file.
When a Viewing Station is connected to the PACS server via a high bandwidth local area network (LAN), downloading of the images is relatively quick and efficient. However, problems may arise when the Viewing Station is located in a remote facility and has a low-bandwidth connection to the PACS Server. For example, if the link between the PACS Server and the remote facility is in the range of 1 Mbit/sec, downloading medical images at the Viewing Station would be very slow and time consuming for medical professionals.
To overcome this problem, medical images may be compressed to reduce the size of the images for transmission. Known methods of compressing DICOM images fall into two main classes. Both classes require the inclusion of a compression engine in the PACS Server and a compatible decompression engine in the Viewer Application.
With reference to FIG. 1, the first class of methods, as illustrated in the block/flow diagram 100 in FIG. 1, entails storing the DICOM images in their original uncompressed form and compressing them in response to requests for the images from a remote viewer. In this method, a PACS Server 116 within a PACS Station 102 stores the DICOM images 115 in their original format in a DICOM database 105 using a DICOM enabled Server Application 106. The DICOM images 115 are received from a Medical Imaging Device 101, such as, for example MRI systems or CAT scan systems, through a high bandwidth LAN connection 114. When an image is requested from a remote Viewer Workstation 104, the PACS Server compresses the image by transmitting the compressed image 108 to an integrated encoder 107 for image compression and sends the compressed image 109 over a low bandwidth connection 103. A Viewer Application 110 utilizes an integrated decoder 112 that is compatible with the encoder 107 in the PACS server 116 to decode the images. The images may be displayed using a viewer 111 or they may be saved locally. An example of this class of methods is provided in U.S. Publication No. 2007/0237402, entitled “Adaptive Selection of Image Streaming Mode,” to Dekel et al.
Referring to FIG. 2, the second main class of known methods for compressing DICOM images, as illustrated in block/flow diagram 200 of FIG. 2, includes employing a compression engine or encoder 215 and a DICOM Enabled Server Application 217 in a PACS server 202 within a PACS Station 203 to compress medical images prior to storing them. DICOM images 208 may be transmitted to PACS server 202 from a DICOM enabled medical imaging device 201 through a high bandwidth LAN 207. After compression, the PACS Server 202 stores the compressed images 209 in its database 216. Upon request from a remote Viewer workstation 205, the compressed images 210 may be sent along a low bandwidth connection 204 to a Viewer Application 212. Similar to the first class of methods, in these systems, the Viewer Application includes a viewer 213 and a compatible integrated decompression engine 214 to decode the images received from the PACS Server. An example of this class of methods is provided in U.S. Pat. No. 6,633,674, entitled “Picture Archiving and Communication System (PACS) Employing Improved Data Compression,” to Barnes et al.
In both known classes the PACS Server Application and the Viewer Application are required to support compatible formats of compression. If one site does not support compression, or the supported formats of both sites are not compatible, using compression for reducing the transmission time of images is not possible. Thus in known methods, if a central FACS Server Application adds or upgrades its compression capabilities, existing Viewer Applications cannot take advantage of the improved capabilities unless they all implement compatible decompression schemes. These are major limitations, as they may not allow the various viewer application and PACS server applications with different levels of support to incorporate improved image compression.
Furthermore, applying known DICOM compression schemes in existing DICOM compatible systems that do not employ compression techniques requires considerable alteration of integrated components of the systems. Altering integrated components of existing DICOM compatible systems to include compression features entails significant verification routines to ensure that other components are minimally or inconsequentially affected. Thus, known methods of DICOM compression do not provide a seamless and efficient means for incorporating compression features within existing DICOM systems.
Accordingly, because of the shortcomings and limitations of known DICOM compression systems, there is a need for methods and systems that seamlessly enhance the efficiency of transferring large volumes of Medical Images to remote stations, without altering any existing PACS and viewer application software and user interfaces.